A bowl with a bottom designed to keep the dish standing balanced, but not stable. The design of the bowl could range from the one shown in the header image to the one below.
The bowl is purposed for serving round/oval fruits in it. It would take some effort putting the fruits in for the bowl to stay balanced and likewise for taking the fruits out.
Why round fruits: round fruits make it easier to keep the balance of the bowl, when you take one out, some of the others might automatically roll to a different place and keep the bowl balanced, it's also easier to rearrange fruits manually in a specific order, for the same purpose, if they are round/oval.
Why do this: To gamify serving/eating of the fruits. Especially in a public ball/catering event people would be interested to see fruits served in such bowls. But even in a home setting, it would be cool to have one or a few of those.
There's also an underlying figurative meaning to this - eating healthy is about keeping the balance and including a substantial amount of fruits/veggies in your diet. Fruits are one of the healthiest things to eat. Fruits=nature=balance. It's a hint to ecocentric thinking.
This would also promote attention and vigilance before eating, you'd have a little meditative moment taking your fruit out of the bowl. And also attentiveness and care while preparing the food (putting fruits in the bowl).
To warn unfamiliar people about the nature of the bowl, the dish could have an upper part designed to hold a banner saying "Caution! Please keep the balance." or a similar one. Here's how it would look: